随机实验是因果推理的黄金标准，但它们并不总是可行的。
"Randomized experiments are the gold standard for causal inference, but they are not always feasible."
真理不会在愤怒中被说出。如果有朝一日真理被说出，那一定是在爱中。
I'm not gonna sing about love if I don't feel it.
Stop being afraid of what could go wrong and start being excited about what could go right.